When we use Huawei NE series routers, we sometimes encounter problems. How can these problems be solved? We provide the Troubleshooting Guide to help you.
If you encounter the Two IPv6 Networks Cannot Communicate Over a Manual IPv6 over IPv4 Tunnel, perform the following steps:
1. Check whether the devices on the IPv4 network between the two IPv6 networks can ping each.
§ If the ping succeeds, go to Step 2.
2. Check whether the IPv6 routes are correctly configured on the source and destination ends.
Run the display ipv6 routing-table command on the source end to check whether the source end has a route destined to the destination end, and run the display ipv6 routing-table command on the destination end to check whether the destination end has a route destined to the source end.
§ If the source end does not have a route destined to the destination end, or the destination end does not have a route destined to the source end, run the ipv6 route-static dest-ipv6-address prefix-length interface-type interface-number command to add a static route to the source end or the destination end.
§ If the IPv6 routes are correctly configured on the source and destination ends, go to Step 3.
3. Run the display ipv6 interface interface-type interface-number command on the source and destination ends to check whether the physical status of the manual IPv6 over IPv4 tunnel is Up.
§ If the physical status of the tunnel interface is Administratively DOWN, run the undo shutdown command in the tunnel interface view and go to Step 4.
§ If the physical status of the tunnel interface is DOWN, perform the following steps.
a. Run the display this command in the tunnel interface view to check whether the tunnel source address, tunnel destination address, and tunnel mode are configured.
· If the tunnel source address, tunnel destination address, and tunnel mode are configured (that is, the source, destination, and tunnel-protocol ipv6-ipv4 6to4 fields are displayed), go to Step b.
· If the tunnel source address, tunnel destination address, or tunnel mode is not configured, run the source {source-ip-address | interface-type interface-number } command, the destination dest-ip-address command, or the tunnel-protocol ipv6-ipv4command to configure a tunnel source address (or a source interface address), a tunnel destination address, or a tunnel mode. Then, go to Step b.
b. Run the display ip interface brief command to check whether the interface mapping the tunnel source address or the IPv4 address of the tunnel source interface exists.
· If the interface mapping the tunnel source address or the IPv4 address of the tunnel source interface exists, go to Step c.
· If the interface mapping the tunnel source address or the IPv4 address of the tunnel source interface does not exist, configure a tunnel source address (or a source interface address) and a tunnel destination address, and then go to Step c.
c. Run the display ip routing-table ip-address command to check whether the route destined to the destination address exists.
· If the route destined to the destination address exists, go to Step 4.
· If the route destined to the destination address does not exist, add a routing protocol or a static route, and go to Step 4.
§ If the physical status of the tunnel interface is UP, go to Step 4.
4. Run the display ipv6 interface interface-type interface-number command on the source and destination ends to check whether the protocol status of the manual IPv6 over IPv4 tunnel is Up.
§ If the status of the protocol is DOWN, run the display this command to check whether the tunnel interface is configured with an IPv6 address.
o If the tunnel interface is configured with an IPv6 address, go to Step 9.
o If the tunnel interface is not configured with an IPv6 address, run the ipv6 address command to configure an IPv6 address for the tunnel interface, and go to Step 5.
§ If the status of the protocol on the tunnel interface is UP, go to Step 5.
5. Run the display this command in the tunnel interface views on the source and destination ends to check whether the source address and the destination address of the tunnel are symmetrical.
§ If the source address and the destination address are symmetrical, go to Step 6.
§ If the source address and the destination address are not symmetrical, run the source {source-ip-address | interface-type interface-number } command or the destination dest-ip-address command to modify the source address or the destination address so the two address become symmetrical.
6. Run the display this command in the tunnel interface views on the source and destination ends to check whether the IPv6 addresses are correctly configured on the two ends.
§ If the IPv6 addresses are correctly configured on the two ends, go to Step 7.
§ If the IPv6 addresses are incorrectly configured on the two ends, run the ipv6 address { ipv6-address prefix-length | ipv6-address/prefix-length } command in the tunnel interface views to reconfigure the IPv6 addresses of the tunnel, and go to Step 7.
7. Determine whether the packets are discarded in the receiving or sending direction and where the packets are discarded.
Run the reset ipv6 statistics command on the source and destination ends to delete statistics on IPv6 traffic, and run the ping ipv6 command and display icmpv6 statistics [ interface interface-type interface-number ] command again to view the statistics on the received and sent ICMPv6 packets on the interface.
§ If the Echoed value in the Sent packets field does not increase on the source end, the source end has not sent any IPv6 packets. Go to Step 8.
§ If the Echoed value in the Sent packets field increases but the Echo replied value in the Received packets field does not increase on the source end, and both the Echo replied value in the Sent packets field and the Echoed value in the Received packets field do not increase on the destination end, the destination end has not received the IPv6 packets that were sent by the source end. Go to Step 8.
§ If the Echoed value in the Sent packets field increases but the Echo replied value in the Received packets field does not increase on the source end, and the Echoed value in the Received packets field increases but the Echo replied value in the Sent packets field does not increase on the destination end, the source end has sent the IPv6 packets, and the destination end has received the IPv6 packets but has not sent any response packets. Go to Step 8.
§ If the Echoed value in the Sent packets field increases but the Echo replied value in the Received packets field does not increase on the source end, and both the Echo replied value in the Sent packets field and the Echoed value in the Received packets field increase on the destination end, the source end has sent IPv6 packets but has not any received response packets, and the destination end has received the IPv6 packets and sent the response packets. Go to Step 8.
§ If both the Echoed value in the Sent packets field and the Echo replied value in the Received packets field increase on the source end, and both the Echo replied value in the Sent packets field and the Echoed value in the Received packets field increase on the destination end, the source end has sent the IPv6 packets and received the response packets, and the destination has received the IPv6 packets and sent the response packets. The fault that two IPv6 networks from communicating over a manual IPv6 over IPv4 tunnel may be caused by an excessively long link transmission delay. Run the ping ipv6 -t timeout destination-address command to increase the timeout period for sending an ICMPv6 response packet.
o If the ping succeeds, go to Step 10.
o If the ping still fails, go to Step 8.
8. Determine where the packets are discarded.
Locate the position based on the direction in which the fault occurs. Perform the following operations to enable IPv6 packet debugging:
<HUAWEI> debugging rawip ipv6 packet
<HUAWEI> debugging ipv6 packet
<HUAWEI> terminal debugging
Run the ping ipv6 -c echo-number destination-ipv6-address command to send five ping packets. Check whether the source end has sent five packets and received five response packets, and whether the destination end has received five packets and sent five response packets. If the related information is not displayed, go to Step 9.
9. If the fault persists, collect the following information and contact Huawei.
§ Results of this operation procedure
§ Configuration files, log files, and alarm files of the device
10. End.
For more troubleshooting cases, see: NE40E Troubleshooting Guide V4.0 (VRPv8)
https://support.huawei.com/enterprise/en/doc/EDOC1000177634
